Type mismatch error

[smalloff]

I have problems with the handler. When I try to call some functions in the body of the handler, I get an error. How to deal with it?

My code:

import prologue
import fastcmspkg/utils
import prologue/core/uid
import tinypool/sqlitePool
import db_connector/db_sqlite
import tinypool/core
import fastcmspkg/templates/nwt

var templates: Nwt

proc hello*(ctx: Context) {.async.} =
  var 
    s: string
     
  s = templates.renderTemplate("main.html", %*{"faa": "super"})    **# If removed, the problem will disappear.**
  resp "Main page from plugin!" & genUid() & ctx.request.hostName() & s



proc Init(app: Prologue, db_pool: ConnectionPool[DbConn], templ: Nwt){.exportPlugin.} =
  SQLITE_POOL = db_pool
  templates = templ
  echo "init plugin " & instantiationInfo().filename
  app.get("/", hello) **# this error!**`

My console log:

d:\nim-2.0.0\projects\fastcms\src\plugins\main page\main_page.nim(32, 6) Error: type mismatch
Expression: get(app, "/", hello)
[1] app: Prologue
[2] "/": string
[3] hello: proc (ctx: Context): Future[system.void]

Expected one of (first mismatch at [position]):
[1] func get(env: Env; key: string): string
[1] proc get(group: Group; route: string; handler: HandlerAsync; name = "";
middlewares: openArray[HandlerAsync] = @[])
[1] proc get[T](self: Option[T]): lent T
[1] proc get[T](self: Option[T]; otherwise: T): T
[1] proc get[T](self: var Option[T]): var T
[3] proc get(app: Prologue; route: string; handler: HandlerAsync; name = "";
middlewares: openArray[HandlerAsync] = @[])

[mrtlsc]

I had the same problem. Proc hello has to be of type HandlerAsync, which is proc(ctx: Context): Future[void] {.closure, gcsafe.}. hello is not GC-safe, because it accesses a global variable templates. At least that's what the compiler should say if you add .gcsafe pragma to the proc.